Direct Fired Heating in Cement Industry

Ever since its inception in the 1840s, people have been building more and more structures with cement;

today, cement is present in virtually every place you look - buildings, sidewalks, parking lots, streets,

houses, ect. Clearly, cement has become such a keystone product in society that there are other

industries are now dependant on the product.

Cement production involves crushing/screening and filtering of various ores, to produce a desired

mixture of particles. Cement manufacturing can be done in three ways: dry, wet or semi-dry processing.

Whether the minerals are wet or dry, the process is the same: dehydrate the quarry ore, crush and mix

them appropriately, and then calcining the mixture to produce, what is commonly called clinker.

The picture above represents the wet process- the slurry is fed to a rotary kiln and subjected to direct

fired process heat via combustion systems. The chemical recation that takes places inside the kiln

transforms the minerals into clickers. In the dry process, the feed is first places into a preheater tower

before being discharged into a rotary kiln. Regardless the feed being wet or dry, the kiln is directly fired

at very high temperatures.

Below is a picture that exemplifies how a rotary kiln works.

After clinker is produced, it is then placed in a grinder and mixed with gypsum to produce the end

product, Portland Cement. Portland Cement is bagged and then sold to end users.

For more information on direct fired combustion systems, please call Stelter & Brinck at 513-367-9300

or visit www.stelterbrinck.com

Keywords: direct fired combustion system, clinker, rotary kiln, direct fired kiln, stelter and brinck,

cement manufacturing, direct fired heating